Transponder antenna

[David Dawood]

I have a PIK-20D and trying to install an AAE-L2 antenna.  The only place I can think of is in the fuselage behind the control hatch, by the O2 Cylinder.  (please see in the attached photo),

One option is install the antenna sideways inside the fuselage but it needs first be bend (using a heat gun) to conform to the fuselage curvature and directly glued to the fiberglass (per antenna instructions). But this installation has the following problems,

 

1- It would be about 4 feet away from the cockpit.  The antenna's instructions require at least 5 feet away to protect the body from high EM emission.

2- It would be installed within less than 4 inches of the aluminum O2 cylinder.  The antenna's instructions require at least 12 inches from any metal object.  (The alternative is to replace the aluminum cylinder with Kevlar cylinder.)

3- As you see in the photo it will be also installed very close to the radio antenna, which the antenna's instructions require a big distance separation to prevent radio EMI.  

The alternative, is to install the antenna on a circular plywood that fit inside the O2 tube and shove the plywood all the way to end of the O2 tube.  However, this installation would be still within 4 inches of the O2 cylinder, less than 5 feet away from my head, and very approximate distance from the radio antenna.  In addition, the antenna will be facing the tail of the glider.  The instructions don't discuss this issue and not sure how to contact the manufacturer. 

So, first anyone know if the PIK 20 gliders comes with already installed transponders antenna?  My glider was built in 1977.  I doubt it but it is worth asking the question.

Otherwise any recommendation of alternative antennas or installation location options,

Thank you,

David       

.  

[Elijah Brown]

That is a dipole antenna, search radiation pattern of a dipole to see how it will radiate. It should be oriented vertically for best performance. Non vertical will still work but link margin is degraded due to polarization mismatch, maybe you won't get radar coverage as far out as you otherwise would (probably doesn't matter for a glider anyway?) I think you'd have to mount it back in the tail boom to get 5ft away from the cockpit, not gonna be easy to get back in there.... 

I will attach a picture of the transponder antenna I put in my 20B, it fits under the instrument panel and uses a ground plane style antenna. If you're worried about the radiation I would use this kind of antenna since most the radiation is below the ground plane, below you where you want it. I don't think transponder radiation is really a big concern anyway due to the extremely low duty cycle, but anyway. 

Are you sure that antenna in the pic is your com antenna? Usually they are built into the fin. 

--
Visit the website at https://sites.google.com/view/pik20/ for files and archives
---
You received this message because you are subscribed to the Google Groups "PIK20" group.
To unsubscribe from this group and stop receiving emails from it, send an email to pik20+un...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/pik20/549971012.6767568.1695663184175%40mail.yahoo.com.

[David Dawood]

Hi Elijah, the plan was to install the antenna vertically regardless where but was not sure if it makes a difference whether facing the side of the aircraft or backswords toward the tail.    I guess, according to your attached photo, it doesn't.  As far as radiation concerns, I am just following the antenna instruction gaudiness.  A radiation meter might be a good device to buy.  I am assuming the antenna in the back is the com antenna, because I see the wire extended forwarded towards the cockpit, under the seat.   The only way to confirm is remove the seat remove the whole seat.  I might consider buy same antenna as yours and do the same installation .  Much easier.   

Thank you so much,

David

[David Dawood]

Elijah, by the way, this is the antenna I purchased from Cumulus Soaring based on their recommendations. I believe direction installation is important,

Thanks,

David 

 

To view this discussion on the web visit https://groups.google.com/d/msgid/pik20/1245708643.2323876.1695737569686%40mail.yahoo.com.

[Alexander Tummes]

I glued the antenna with 5 min resin to the right inside of the fuselage as shown in the photo

[127178]

Evening all,

I just stumbled onto a YouTube video by Halmer Lakeman titled Transponder Antenna Drag from January 5, 2021.  He shows the difference between a wing and a rod type antennas.  He attached yarn to the tips of each and amazingly the rod type appeared to have less disturbance  of the yarn.  He mounted each one down low on the right side of the ship just aft of the gear door.  His altimeter jumps around a little bit and because it and the airspeed use the same static port the wing type appeared to be causing a disturbance in the airflow over the static port.

I wish I knew how to copy a link to this video but I don't have a four year old here to help me.

I hope this information is of some use to you.

Keith 

[Peter Jarvis]

Here's some info from a club member near Houston, TX..   There's a lot of traffic there as well as around Faultline Flyers (North of Austin where I fly my pik20D)..  This Houston club member as well as a lak-12 club member in my club has gone this route and they're both very happy with the install.  I think I'm going to do the same thing.   

Using this antenna:

http://www.aircraftspruce.com/pages/av/antenna_transponder/antennasystems1.php

mounted inside the nose. (PDF)

--

Visit the website at https://sites.google.com/view/pik20/ for files and archives
---
You received this message because you are subscribed to the Google Groups "PIK20" group.
To unsubscribe from this group and stop receiving emails from it, send an email to pik20+un...@googlegroups.com.

To view this discussion on the web visit https://groups.google.com/d/msgid/pik20/75eb0d53-0216-41ad-b1b5-3e1e225fa84dn%40googlegroups.com.

[Alexander Tummes]

Installed my antenna next to the gear.